The present invention generally relates to optical image scanning systems, and more particularly to an optical image scanning assembly wherein light reflected from an image being scanned is transmitted to an optical sensor through an optical shutter assembly via a light guide assembly. The optical image scanning assembly may also function as a display assembly wherein color components for light emitted by display elements or pixels of the display assembly are premixed and transmitted along the light guide assembly to the pixels to form the displayed image.
Optical image scanning systems typically employ light-sensing equipment to capture an image of a subject such as indicia contained on a medium such as paper, an object, or the like. Such systems normally translate the image into a digital signal that can be manipulated by optical character recognition (OCR) software or graphics software. Optical image scanning systems are available in a number of configurations including xe2x80x9cflat bedxe2x80x9d wherein a scanning head is passed over the subject which is held stationary, xe2x80x9cfeedxe2x80x9d wherein the subject is pulled across the scanning head which is held stationary, xe2x80x9cdrumxe2x80x9d wherein the subject is rotated around a stationary scanning head, and xe2x80x9chandheldxe2x80x9d wherein a user passes a handheld scanning head over the subject. Optical image scanning systems are also commonly utilized in facsimile machines, photocopiers, and the like.
A common problem of existing scanning systems is the use of moving components such as gears, motors and the like to move the scanning head containing the light sensing equipment relative to the subject being scanned. Such moving components are subject to slippage, inaccuracy, breakage and/or wear which may cause the scanning system to not function properly. Known to the art are image scanning systems which project an image on a document onto an optical sensor through an optical shutter by passing light through the document. However, such systems are limited to use with thin media, such as thin paper, wherein the media is capable of becoming at least translucent when placed in front of a strong light source. Such systems cannot be used to scan images from opaque media such as thick papers, cardboard, books, three-dimensional objects, and the like. Consequently, the practical usefulness of such systems is limited to applications involving the scanning and verifying the authenticity of paper currency.
Accordingly, it would be advantageous to provide an optical image scanning assembly wherein light reflected from an image being scanned is transmitted to an optical sensor through an optical shutter assembly via a light guide assembly. In exemplary embodiments, such a system would also be capable of functioning as a display assembly yielding a higher fidelity image than is possible using existing liquid crystal displays (LCDs).
The present invention is directed to an optical image scanning assembly wherein light reflected from an image being scanned is transmitted to an optical sensor through an optical shutter assembly via a light guide assembly. The optical shutter assembly is made substantially opaque except for one or more selected optical shutter elements that are made substantially transparent or opened. Light is then reflected from the medium containing the image to be scanned through substantially transparent shutter element or elements and transmitted to the optical sensor via a light guide assembly. The image may then be scanned by advancing selection of shutter element or elements that are opened across the medium.
In an exemplary embodiment of the present invention, the image scanning assembly is comprised of an optical shutter assembly including a plurality of individually actuateable shutter elements capable of substantially allowing or blocking transmission of light, for example, pulses of light emitted by a light source, onto an object being scanned, wherein at least a portion of the light is reflected from the object through the optical shutter assembly. Light reflected from the object through the open shutter element or elements of the optical shutter assembly is conducted to the optical sensors via a light conducting assembly.
The optical scanning assembly may further be capable of functioning as a display assembly wherein color components for each display element or pixel of the display assembly are premixed so that the display elements provide a true color instead of separate red, green and blue components of that color. In this manner, the display assembly of the present invention is capable of providing a higher fidelity image than is possible using existing display technologies such as LCDs or the like.